Induction apparatus



Mal'ch 9 c. G. s. LINDBLOM 2,192,553

INDUCTION APPARATUS Filed March '24, 1939 Patented Mar. 5, 1940 UNITED STATES iATENT OFFICE INDUCTION APPARATUS Carl Sweden,

Gustaf Samuel Lindblom,

Stockholm,

assignor to Svenska Ackumulator Aktiebolaget Jungner, Stockholm, Sweden '7 Claims.

The present invention relates to induction apparatus, for instance for illuminating devices, in which the source of current is connected to the primary winding of the induction apparatus over contacts controlled by the hammer armature of the apparatus and in which a discharge tube, for instance a neon. tube or the like, is connected to the secondary winding of the apparatus.

At the relative high primary strengths of current, which generally are used, it has been proved that, also when using the best materials in the contacts controlled by the hammer armature, a transfer of metal takes place from the positive contact to the negative one. Through such a metal transfer a crater will be formed in the positive contact, whereas a pike will be formed on the negative contact. Within a shorter or longer time, depending on the current density, the said pike grows larger, and flakes are formed, which cause a short-oircuiting of the contacts, so that the induction apparatus and, as a consequence, the devices operated by the same are wholly put out of function.

The present invention has for its object to avoid the above mentioned drawback and consists substantially in this that a pole reversing switch is placed in the primary circuit of the induction apparatus. Preferably, the said reversing switch may be combined with or made as a circuit breaking switch and so constructed that, cit-er a circuit breaking has taken place, a returning movement to the foregoing switch on position cannot be effected. The reversing switch can be arranged to be operated manually or automatically, for instance by means of a clock work or the like, which effects the required pole-reversing at desired intervals.

In the annexed drawing an embodiment of a device according to the invention is shown diagrammatically. Fig. 1 illustrates a reversing switch made as a rotary circuit breaker and an induction apparatus connected thereto. Fig. 2 is a top view of an associated primary source of current in the form of a storage battery.

to Fig. l, i and 2 designate two circcntact bars relating to the reversing l, the i of which is connected to the one end the primary winding 4 of the induction ap by means of a wire 3, whereas the second car in the ordinary way is interruptedly connected to the other end of the said primary winding through a wire 5 and over the" contacts l and zl controlled by the hammer-armature 6. Connected to the secondary winding 9 of the induction apparatus is a neon tube In or the like.

Sliding against the contact bars I and 2 are the outer ends of two mutually electrically insulated contact springs H and I2, respectively, which are secured to a central rotary shaft IS. The inner ends of the contact springs H, l2 can be moved into contact with stationary pairs of contacts Mo, I511, Mb, [5b, lac, I50 and Md, l5d, respectively, arranged in groups, the contacts l4a|4d of which on the one hand and the contacts Ida-I503 on the other hand are alternately connected to the negative pole and the positive pole, respectively, of the battery 20 through wires l6, l1, I8 and I9.

Firmly secured to the shaft l3 of the switch is a ratchet wheel 2| meshing with a stationary spring pawl 22, which permits rotation of the shaft and the springs H and I2 and also of the ratchet wheel 2! in the clock-wise direction, but prevents rotation in the opposite direction.

In the position denoted by II in Fig. l, in which the inner ends of the contact springs H,

12 are into contact with the corresponding pair of contacts its, Ma, the contact 8 of the induction apparatus is connected to the negative pole of the battery 2%] over the wire 5, the contact bar 2, the spring E2, the contact Ma and the wires iii and I8, whereas the contact I of the armature 6 is connected to the positive pole of the battery over the primary winding 4, the wire 3, the contact bar l, the spring I l, the contact Ito and the wires l1 and I9.

When rotating the contact springs ll, [2 to the position IIIIII a circuit breaking occurs, and when further rotating the springs to the position IV the contact 8 of the induction apparatus will be connected to the positive pole of the battery 20 over the wire 5, the contact bar 2, the spring l2, the contact Mb and the wires l1 and i9, whereas the armature contact 1 will be connected to the negative pole over the primary winding 4, the wire 3, the contact bar I, the spring II, the contact [5b and the wires l5 and i8. Thus, a pole reversing has been effected.

When further rotating the contact springs II, It in the direction mentioned, firstly a circuit breaking takes place in the position 1-1 and then again a pole reversing in the position V over the contacts Me and Me. In the following position IIIIII a circuit breaking will again take place, and in the position VI a pole reversing again is eliected over the contacts Md and I5d.

Through the said reversing, which may be effected manually or automatically at intervals, as mentioned, the described deformation. of the contacts I and 8 will be efiectively prevented,

and the operation of the induction apparatus will be undisturbed. Further, the pawl and ratchet means 22, 2! positively prevents the contact springs ll, I2 from being moved back into a foregoing position after a circuit breaking having been effected.

At an exchange of battery it may happen that at the connection of the new battery a pole reversing may be made, for instance through inadvertency. Thus, the result will be that at the consecutive adjustment of the reversing switch into the new switch-on position no pole reversing will take place with respect to the contacts I, 8 and that consequently the said contacts will have to work with the same pole connections during two periods, which can be disadvantageous, particularly in case of the said periods being long.

In order to avoid the said drawback an arrangement according to Fig. 2 can be made. In the said figure, 2!) denotes the battery as is the case in Fig. 1. The separate cells are placed in a casing 23. The contact bars of the terminals of the battery are denoted by 24 and 25, respectively, and the first mentioned bar 24 adapted to be connected to the positive terminal of the battery is made so long, as to project outside the battery casing. As a consequence, in order that the said bar may be connected to the corresponding terminal, a recess 26 must be made in the associated wall of the battery casing. The negative bar 25 is so short that it can be conneoted to its terminal without any corresponding recess being made in the wall of the casing. Evidently, it is possible to apply the last mentioned bar 25 to the positive terminal, but on the other hand the bar 24 cannot be applied to the negative terminal. As a consequence, there is no risk for a pole reversing at an exchange of battery. For the same purpose the battery terminals may be made of difierent thickness, and the bars 24, 25 may be provided with corresponding holes of different sizes, so that a confusion cannot be made.

What I claim as new and desire to secure by Letters Patent of the United States of America is:

1. In combination, an induction apparatus comprising a primary winding, a secondary winding, an oscillatory armature operated by said primary winding, and contacts in the circuit of said latter winding controlled by said armature upon the oscillations thereof, a pole reversing switch in the circuit of said primary winding, and means permitting movements of said switch in the one direction only.

2. In combination, an induction apparatus comprising a primary winding, a secondary winding, an oscillatory armature operated by said primary winding, and contacts in the circuit of said latter winding controlled by said armature upon the oscillations thereof, a pole reversing switch in the circuit of said primary winding, and means for temporary breaking said circuit when effecting said pole reversing.

3. In combination, an induction apparatus comprising a primary winding, a secondary winding, an oscillatory armature operated by said primary winding, and contacts in the circuit of said latter winding controlled by said armature upon the oscillations thereof, a combined pole reversing and circuit breaking switch in the circuit of said primary winding, and means permitting movements of said switch in the one direction only.

4. In combination, an induction apparatus comprising a primary winding, a secondary winding, an oscillatory armature operated by said primary winding, and contacts in the circuit of said latter winding controlled by said armature upon the oscillations thereof, a pole reversing switch in the circuit of said primary winding, means for temporary breaking said circuit when effecting said pole reversing, and means for preventing a return movement of said pole reversing switch into a foregoing position after the circuit breaking having taken place.

5. In combination, an induction apparatus comprising a primary winding, a secondary winding, an oscillatory armature operated by said primary winding, and contacts in the circuit of said latter winding controlled by said armature upon the oscillations thereof, a combined rotary pole reversing and circuit breaking switch in the circuit of said primary winding, and means permitting rotation of said switch in the one direction only.

6. In combination, an induction apparatus comprising a primary winding, a secondary winding, an oscillatory armature operated by said primary winding, and contacts in the circuit of said latter winding controlled by said armature upon the oscillations thereof, a rotary pole reversing switch in the circuit of said primary winding, and means permitting rotation of said switch in the one direction only.

7. In combination, an induction apparatus comprising a primary winding, a secondary winding, an oscillatory armature operated by said primary winding, and contacts in the circuit of said latter winding controlled by said armature upon the oscillations thereof, a direct current source in connection with said primary winding, differently shaped terminal connections for said source, a pole reversing switch in the circuit of said primary winding, and means permitting movements of said switch in the one direction only.

CARL GUSTAF SAMUEL LINDBLOM. 

